Darren

I've been searching the archives for this answer but I'm having trouble finding it -- I'm sure it's there.

What are the differences between the GT3RS and 996 and 997 Cup Car front uprights? I've been told conflicting things and not sure how to verify...

Thanks!

luiscarlos

Cup uprights are like more reinforced but sure some angles also change..

Geoffrey

There have been geometry changes between the 996 Cup, GT3RS, GT3RSR, and 997 Cup uprights both front and rear that affect the bump steer of the car.

Darren

Thanks Geoff, thats my question what exactly are the differences.

Geoffrey

The differences are in the location of the lower ball joint and the tie rod attachment points.

Darren

I know, that's why I'm asking. I'm lowering my car quite a bit and putting on Moton triples essentially for the Cup Car so I'm trying to figure out which uprights are going to allow for the best geometry.

Red9

Anyone got a comment on that? It sort of seems obvious that each newer model should have been a step forward-was that the case?

va122

Call Lex at Moton, I got the tripples for the cup and there wasn't enough travel for my ride height. either rebuild them for your car or get the cup uprights.

Antonov

I was under the impression that cup uprights have revised roll center as well

Ed Newman

Darren, did you ever do this swap? Is there anything else needed besides just the uprigth itself? The bearing and bearing lock plate have different part #'s ???

Darren

Ed,

Yes I did -- The bearing is actually the same part, and the 996 hubs work just fine. The lock plate is different -- it has 6 bolts, so you need the bolts and plate from the dealership -- 2004 gt3 rs.

I haven't figured out the heat shields yet -- it might not be a huge issue because the brakes won't get nearly as hot as the stock 996 brakes, but in general heat will destroy the abs sensors so it's probably a good idea to work out the heat shields.

The tie rod ends worked just fine -- mine were almost all of the way in with the 996 uprights, the distance to the gt3rs uprights is about 1" greater on each side of the car. There is still enough engagement on the stock tie rod ends, but you might want to consider getting the gt3rs tie rod ends (I didn't).

The bracket for the hydraulic line is different -- the GT3RS part is $53 for each side of the car, but what I did was use a 1/4" ID by 1" long round chrome spacer and a 1 1/4" long 6 mm bolt. The spacer goes between the upright and the brake line bracket. This secured it very well but there are probably other solutions for this.

It's necessary of course to install GT3 front brakes, which then also require GT3 rear brakes or else the bias is totally wrong.

Ed Newman

So you put in the 996 GT3 RS ones? I was looking at the cup one? I have stock GT3 ones right now for my GT3 brakes. You run at the NASA race up at the Glen last week? Clipped the wall?

Darren

Yup note my brake bias point Fronts locked up and I couldn't get it back under control.

The 996 gt3rs (street car) part is the same as the 997 cup part, according to my research. I believe this was done for homoligation reasons.

Ed Newman

So you only changed the front brakes? That could definitely **** it off.

Not sure about that.

996 GT3 RS 996.341.157/158.92
996 Cup (05) 996.341.157/158.91
997 Cup (06) 997.341.157/158.90

You going to Thunderbolt?

Darren

All three are Motorsports part numbers, and should be essentially the same part. Normally if its .90, .91, .92 they would have very slight differences but you never know.

I wonder if you ordered the .90 from Motorsports if they would actually send the .92......

In any case it did what I was trying to do, which was to lower the position of the control arm ball joint relative to the center of the axle.

I'll be at Thunderbolt this weekend for an RTR DE and then NASA NE Thunderbolt over Thanksgiving for that race weekend.